Door knocker



FIG. 1 is a top perspective view of a door knocker showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a left elevational view thereof;

FIG. 5 is a right elevational view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof;

FIG. 8 is a bottom perspective view thereof; and,

FIG. 9 is a left, perspective view thereof.

The broken lines shown in the figures depict portions of the door knocker that form no part of the claimed design. 

CLAIM The ornamental design for a door knocker, as shown and described. 